It is well known that a silver halide color photographic material contains coupler(s) and that the coupler(s) in the material is/are reacted with an oxidation product of an aromatic primary amine color developing agent, that has been formed by oxidation with the exposed silver halide in the material as an oxidizing agent, to form a color image composed of indophenol, indoaniline, indamine, azomethine, phenoxazine, phenazine and the related dyes. In such a photographic system, subtractive color photography is used, and color images are formed of yellow, magenta and cyan dyes.
Of these, for producing cyan color images, phenol or naphthol couplers are generally used. However, since these couplers have unfavorable absorption in a green range, they have a serious problem that they noticeably lower the color reproducibility. Therefore, it is desired to overcome the problem.
As a means for overcoming the problem, heterocyclic compounds as described in U.S. Pat. Nos. 4,728,598 and 4,873,183 and European Patent 249,453A2 (corresponding to U.S. Pat. No. 4,818,672) have been proposed. However, these have a fatal problem that the coupling activity thereof is low. As couplers free from the problem, pyrroloazoles described in European Patent Laid-Open No. 0491197A1 (corresponding to U.S. Pat. No. 5,256,526) have been proposed. These couplers are excellent in point of the coupling activity of themselves and the color hue of the dyes to be formed therefrom. However, the pyrroloazotes disclosed in the patent had a problem that the color density of the dyes to be formed from them often fluctuates due to the fluctuation of the composition of the bleach-fixing solution (hereinafter referred to as "blix solution") to be used for processing the photographic materials containing the couplers. The fluctuation of the color density of the dyes formed was noticeable especially when the concentrations of thiosulfato ions and sulfito ions in the blix solution vary during continuous processing. The couplers had another problem with respect to the fastness of the color images to be formed therefrom in that the fastness of the image part having a relatively low color density is inferior to that of the image part having a high color density. For these reasons, it has been desired to improve the couplers in order to put them into practical use. In addition, the couplers had still another problem that they give a large cyan fog in the unexposed areas of the photographic materials during continuous .processing. Given the situation, it has been desired to improve the couplers so as to overcome the problems.